Kinetic and calorimetric study of the adsorption of dyes on mesoporous activated carbon prepared from coconut coir dust

Adsorption of Reactive Red 120 from aqueous solutions by cetylpyridinium‐bentonite

“…3) illustrating that π interactions between Lewis acid sites and oxygen planes of the clay sheets and π -π dispersive interactions between aromatic rings, and -N N-and -N C -C C -groups of the dye molecule also contribute to the adsorption. 22,32 However, the incorporation of the van der Waals forces between the dye species and surfactant cations, and among the organic species themselves, cannot be ruled out.…”

“…The endothermic adsorption process of RR 120 on CP-bentonite, which shows a reversal to that generally seen, that is the observation of the negative enthalpy change with the entropy decrease of the system during adsorption, may be interpreted through displacement of more than one pre-adsorbed water species by each dye molecule. 32 This endothermic effect instigates an increase on the entropy during the duration of the adsorption process. Therefore, the positive S value may be taken as a measure of the number of disordered water molecules within the CP-bentonite/RR 120 composite and also implicates an increasing randomness at the solid-solution interface.…”

Lead and Cadmium Removal from Aqueous Medium Using Coir Pith as Adsorbent: Batch and Fixed bed Column Studies

“…Studies have shown that materials can be treated physically, chemically or thermally to enhance adsorption properties (Babu and Ramakrishna, 2003). Rice husk (Chuah et.al., 2005, Amarasinghe et al, 2005, tea waste (Amarasinghe and Williams, 2007, Malkoc and Nutoglu, 2005, saw dust (Sciban, 2006, Shukla, 2002, tree leaves and barks (Baig, 1999, Palma et al, 2003 and coconut husk based products (Santhy and Selvapathy, 2006, Namasivayan and Sangeetha, 2006, Macedo et al, 2006Shukla et al, 2006, Conrad and Hansen, 2007 have all been tested for their adsorption characteristics for dyes, heavy metals and other organic matter.…”

Specifications of the Quality of Granulated Activated Charcoal Used in Water Systems Treatment in Hemodialysis Centers in Brazil

“…Besides, additional information regarding the distribution of the sizes of the activated charcoal pores can be obtained by comparing the adsorption characteristics of adsorbate by taking those obtained from adsorption data in gaseous phase. Methylene blue (MB) has been widely used as an adsorbate to estimate the adsorption capacity of CA from continuous in fixed bed or batch experiments (Kumar & Sivanesan, 2006;Macedo et al, 2006;Zhang et al, 2006). Studies on MB adsorption equilibrium in activated charcoal can provide important information about the selectivity of these adsorbents regarding this molecule, given that the MB is accessible to the charcoal pores with an inner diameter greater than 1.5 nm, being important for the characterization of the secondary micropores (0.8 <di <2.0 nm) and mesopores (2 nm < di < 50 nm) mainly, besides being a model compost used for predicting the adsorption of organic contaminants found in industrial effluents such as textile dye and microcystines (Barton, 1987;Baçaoui et al, 2001).…”